<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>定位-固定定位二</title>
    <style>
        .content {
            width: 80%;
            height: auto;
            margin: 15px auto;
        }

        .back {

            /* 固定定位 */
            position: fixed;
            right: 0;
            bottom: 0;

            text-align: center;
            padding-top: 25px;
        }

        .left {
            /* 固定位置 */
            position: fixed;
            left: 0;
            bottom: 0;

            text-align: center;
            padding-top: 25px;
        }
    </style>
</head>

<body>
    <!-- 锚点 -->
    <a id="top"></a>
    <div class="content">
        <img src="box.png" />
    </div>
    <div class="back">
        <img src="ad-r.png" />
    </div>
    <div class="left">
        <img src="adv.jpg" />
    </div>
</body>

</html>